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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 3 |
| 4 | 8 |
| 5 | 22 |
| 6 | 68 |
| 7 | 217 |
| 8 | 720 |
| 9 | 2438 |
| 10 | 8412 |
| 11 | 29414 |
| 12 | 104048 |
| 13 | 371516 |
| 14 | 1337352 |
| 15 | 4847637 |
| 16 | 17679264 |
| 17 | 64823110 |
| 18 | 238820780 |
| 19 | 883634026 |
| 20 | 3282065072 |
| 21 | 12233141908 |
| 22 | 45741298616 |
| 23 | 171529836218 |
| 24 | 644952132448 |
| 25 | 2430973304732 |
| 26 | 9183676744088 |
[1,1,2,3,8,22,68,217,720,2438,8412,29414,104048, 371516,1337352,4847637,17679264,64823110, 238820780,883634026,3282065072,12233141908, 45741298616,171529836218,644952132448, 2430973304732,9183676744088] |